Air-feed lock



W. A. SMITH AIR FEED LOCK Flel June 20. 1925 May 25 A INVENTOR.

@wwf Patented May 25, v1926.Y

UNITED STATES 1 1,586,269 VPia-'rinvii OFFICE.

WILLIAM A. SMITH, OF ATHENS, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEYCITY, NEW JERSEY, ACORPOBATION OF NEW JERSEY.

AIR-FEEDy Loox.`

Application filed .Tune 2O,V 1925. Serial No. 387,477.'

This invention relates to fluid actuated rock drills, but more particularly to an air feed lock for rock drills of the stoper type.

An object of the invention is to prevent accidental withdrawal of a rock drill from the working face.

Another object is to equip the feeding element of the rock drill with a lock for preventing recoil o-f the machine caused by the hammer piston striking the drill steel.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention consists `ofthe combination of elements, features. of construction `and arrangement of parts, having the general mode of operation substantially as hereinafter described and more particularly pointed out in the appended claims and illustrated in the accompanying drawings, in whichi Figure 1 is a View of a rock ydrill in elei manner in whichthe air feed lock is secured n to the feeding cylinder and the manner iny which. the locking device cooperates with the piston rod for preventing'downward movement of the cylinder with respect to said rod,

Figure Sis a view taken through Figure 2 on the line 3-,-3 looking in the direction of the arrows, `and v y k Figure fi is a View taken through Figure Zon the line 4-4 looking in the direction of the arrows.

Referring to the drawing in which is illustrated one embodiment of the invention, A designates a hammer cylinder supporting at its forward` end a front head B. The cylinder A and the front head Bare held in operative position by means of spring pressed side bolts C. Disposed within the front head' B is a drill steel D to receive the blows of a hammer piston (not shown) reciprocating within the cylinder A. vAny suitable method may be employed for ro-y tating the drill steel within the drill hole. In this instance, a gear motor (not shown) is arranged at the rearward end of the cylinder A and encased by a. gear casing E. Pressure fluid to the drill is supplied through a suitable conduit F connected to a back head vGr which forms a4 closure for the rearward ends of the cylinder A and the gear motor casing E. The

l pressure fluid entering the back head tothe by means of a nut K.

To the end that the drill may be advanced A toward the working facey as the drill steel D penetrates thek rock, a feed cylinder L is secured to vthe. back head as by means` of bolts O which extend through the back head G, the motor casing E and the cylinder A for holding said members in operative position with respect to each other. Disposed freely rotatable. within the cylinder L is a piston 'rod P carrying a piston head Q at o-ne end and having at the other end a rock engaging pointer R. y

In accordance with the practice of the invention, a bearing member S, split longitudinally on one side as at T, is arranged at the front end of thecylinder L. Any suitable means maybe provided for securing the member S against movement with respect to the cylinder L. In this instance, a hole U is formed through one side of th-e member Sv to receive a bolt- 'V` provided with a suitable nut IV whereby the member S may be clamped firmly in position. In Aorderto insure greater rigidity between the member S and the cylinder L, said member S isprcvided with `an inwardly extending shoulder X to abut theY end'of the cylinderL. 'A bushing Y is` in this instance inserted in the frontend of the cylinderL to serve as a guide for the rod P.

Suitable means are provided for preventing accidental withdrawal of the drill from the working face and also to prevent recoil ofthe machine while the drill isin operation.' '-To this end, a pair of lugs Z are formed on the member S to serve as guiding members and bearings for an eccentric member b,-which in thisy instance is provided with'a removable shaft@ journalled in the lugs Z. The shaft c is preferably provided with a polygonal portion.' ai to cooperate with a correspondingly formed bore e formed in the eccentric member b for pre-` venting relative rotative movement between the said` eccentric Z)V and the. shaft; c. Any suitable means may be provided for manu.- ally operating the member Zi; in this instance a lever f is formed.integrally with the sliaftc andfa flange g for-med at the juncture of tlie lever f and the shaft c serves as a sto-p for preventing longitudinal movement oftheshaft in one direction. Movement of the shaft in the opposite direction may. be prevented by insertingl a pin 7L through the end of; the shaft c or by any other suitable and convenient means.

In order toincrcase the line of contact'bctween the eccentric member Z1' and the piston rodP, the contacting face of said member isformed concave to coliform to the periphery'of said piston rod. rllothe end that the` eccentric member Z) may be normally heldin frictional engagement with the piston rod P, a plunger /c is arranged? slidably in a bore 0 formed in the bearingmember S. A' spring p" arranged in back ofthe-plunger forces the plunger downwardly against a flat face Q formed on the member b andthus holdssaid member in engaging position.

In the operation of the device, assuming that the machine is in operation and-'consequently is being fed inthe direction of the work as tliedrill moves upwardly7 along the piston rod' P; the member Z) slides freely along the: face offsaid rod. Then tlieihammer piston strikes the drill steelD, the ma'- chine tends to recoil, andsincethe plunger zholds the member bconstantly in readiness for engaging the piston rod- P, downward movement. or recoil, of the drill is preventedl Similar-ly, ifV the air supply to the drill should suddenly become cut oil'. or fail for other reasons, the drill' would be prevented from falling'away from the work. In order to lower the drill, tlie eccentric member L may be moved manually to the position shown by the dot' and dash lines in Figure Q. The pressure fluidfrom the feeding cylinder may then be released.

lf claim:

l. In anl air'feed lock for rockdrills, the combinati-on of a feeding cylinder with a piston rod rotatable in the cylinder, a bearing secured to the=cylinder, and mea-nssupported by the bearing in frictional engagement with the rod for preventing recoil of the cylinder during thel operation of the drill.

2. In an air feed lock for rock drills, the combination of a feeding cylinder with a piston rod freely rotatable in the cylinder, a bearing clamped to the cylinder, and means supported by the bearing to cooperate f'rictionally with the rod for automatically preventing recoil of thefcylinderon the rod during theoperation of the drill.

3. In an air feed lock for roel; drills, the combination of a feeding cylinder with a piston rod freel7 rotatable in the cylinder, a bearing clamped to one end of the cylinder, andA a locking. member supported by the bearing in constant frictionalV engagement witlrthe rod to prevent recoil of the cylinder with respect to the rod during` the operation of tlie'd'rill.

el. n an air feed lock for rock drills, the combination of a feeding cylinder with a piston rod free-ly rotatable in the cylinder., a bearing clan'iped to ,one end of the cylinder, and an eccentric locking member supported by the bearing for frictionally engaging the rod to prevent recoil of the cylin@ der with respect to the rodduring'the voperationiof the drill.

In an air feed loch' for rock drills.` the combination of a feeding cylinder with a piston rod' freely rotatable in thecylinder, a bearing clamped to oneeudf of the cylin der, an eccentric locking member supported bythe bearing for frictionally engaging the rod to prevent recoil of the cylinder on the rod, and means for holding said member normally in engaging position.

6. In an air feed lock for rock drills, the combination of a feeding cylinder' with a piston rod, a bearing on one end of the cylinder, a boltv for clamping the bearingvv on the cylinder, saidl bolt engaging one side of the cylinder` for preventing' relative movement between the cylinder and the bearing, an eccentric locking member mounted pivotally in thebearingand having'a concaveface for engaging' the rod to prevent movement of tliecylinder in one direction with respect to the rod, and a` spring pressed plunger associated with the locking member for hold'- i.1igsaid concave face normally against' the rod.

7. In an air feed lock for rock drills, the. combination of? a feedingv cylinder with a piston rod. a bearing` on one end'v of the cylindena bolt' for clamping the lbearing'on thecylinder, saidbolt engaging oneA side of the cylinder for preventing relative move# ment between the cylinder and the bearing, an eccentric locking member mounted pivotally in the bearing and hav-ing a concave face for engaging the rod to prevent move* ment of the cylinder in one direction with respect to the rod, a spring pressed plunger associated with the locking member for holding` said concave face normally against the rod, and a. handle whereby saidV locking n'lember may be oscillated manually;

In testimony whereof I have signed' this specification.

llTllililAMi A'. SMIIH; 

